Earth's rotations and revolutions
These two short online tutorials discuss how the earth rotates and then the earth's revolutions.
These two short online tutorials discuss how the earth rotates and then the earth's revolutions.
In the first URL, the YouTube video explains why earth has spring, summer, autumn and winter seasons. The second URL summarizes the key takeaway points.
Part 1: Equivalent fractions and the simplest form of a fraction
Part 2: Examples of equivalent fractions
Part 3: Common mistakes and misconceptions
Part 1: Proper, improper and mixed fractions
Part 2: Examples of proper, improper and mixed fractions
Part 3: Common mistakes and misconceptions
Use two methods to find the sum of mixed numbers: improper fractions and mixed numbers
This 32 minute long YouTube video investigates the water contamination problems in Tanzania, with specific focus on Dar Es Salaam.
This 11 minute long YouTube video describes the various causes and types of water pollutants.
This YouTube video investigates what water pollution is and some examples and effects of water pollution.